JP4529319B2 - Semiconductor chip and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin-encapsulated semiconductor chip and a manufacturing method thereof.
[0002]
[Prior art]
A semiconductor chip is usually used by forming each element on a wafer, then cutting the wafer, mounting, and then sealing with a resin.
In addition, as a method of cutting the wafer, for example, the surface of the wafer is scratched with a diamond cutter or the like, and the wafer is cleaved using a cleavage (scribe method). For example, diamond abrasive grains are applied to the surface of a metal disk. There are a method of cutting the wafer halfway (half-cut) using a fixed dicing saw, and a method of cutting to the end using a dicing saw (full cut).
[0003]
[Problems to be solved by the invention]
However, the conventional semiconductor chip needs to be handled with care so as not to damage the element during mounting, and is not easy to handle.
In addition, in the manufacturing process using the scribing method, chipping and cracks may occur where the corners of the semiconductor chip are chipped. There was a problem in the manufacturing process that it was necessary.
Especially when using high-hardness wafers, more careful parameter fine adjustments are required, and these fine adjustments rely heavily on human senses and experience, making it difficult to automate the cutting process. there were.
Further, there is a problem that the sapphire substrate cannot be fully cut using a dicing saw.
[0004]
Therefore, a first object of the present invention is to provide a semiconductor chip that can be easily handled.
A second object of the present invention is to provide a semiconductor chip manufacturing method that can easily prevent chipping and cracks and can be easily automated.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a nitride semiconductor light emitting device according to the present invention includes an n-type semiconductor layer in which an n electrode is formed, a light emitting layer made of a nitride semiconductor, and a p electrode formed on a substrate. A nitride semiconductor light emitting device comprising a bump formed on each of the n electrode and the p electrode.
Formed resin sealing body made of a resin having a containing Mikatsu translucent phosphor to substantially cover said chip except for the tip portion and the lower surface of the substrate of the bump, and the resin sealing body It has a side surface perpendicular to the substrate.
By configuring in this way, a desired emission color can be realized by mixing the light emitted by the semiconductor layer and the light emitted by the phosphor.
In the nitride semiconductor light emitting device according to the present invention configured as described above, since the resin sealing body is formed except for the tip portion of the bump and the lower surface of the substrate, the n-type and p-type semiconductors are formed. Since the layer and each electrode can be protected, handling during mounting can be facilitated. Here, in this specification, the upper surface means not the upper and lower sides when mounted, but the surface on the side where the semiconductor layer and the electrode layer are formed in the nitride semiconductor light emitting device, and the lower surface means the semiconductor layer is formed. This is the opposite of the surface.
[0006]
In the nitride semiconductor light emitting device of the present invention, the n-type semiconductor layer may include one or more nitride semiconductor layers, and the p-type semiconductor layer may include one or more nitride semiconductor layers. Good.
[0007]
Furthermore, in the nitride semiconductor light emitting device of the present invention, it is preferable that the resin encapsulant has a bottom surface located substantially on the same plane as the lower surface outside the lower surface of the substrate. Since a relatively thick resin sealing body can be formed outside the side surface, the n-type and p-type semiconductor layers and the electrodes can be more effectively protected.
[0009]
In the nitride semiconductor light emitting device of the present invention, the resin encapsulant may include reflection / scattering particles. When configured in this manner, the resin sealing body emits light particularly when mounted so as to emit light from the lower surface of the substrate. The light extraction efficiency can be improved.
[0010]
A method for manufacturing a nitride semiconductor light emitting device according to the present invention is a method for manufacturing a nitride semiconductor light emitting device by separating a plurality of devices formed on a wafer for each device,
A groove forming step of forming a separation groove between the elements of the wafer;
A resin forming step of forming a translucent resin on the wafer on which the separation groove is formed and filling the separation groove with resin, and curing the resin;
A polishing step of polishing the lower surface of the wafer until the cured resin of the separation groove is exposed;
A cutting step of cutting the cured resin of the separation groove,
The nitride semiconductor light emitting device includes an n-type semiconductor layer in which an n-electrode is formed, a light-emitting layer made of a nitride semiconductor, and a p-type semiconductor layer in which a p-electrode is formed on a substrate obtained by cutting the wafer. And comprising
Bumps are respectively formed on the n electrode and the p electrode,
In the resin forming step, a phosphor is contained in the resin, and the resin is formed so as to substantially cover each element except for a tip portion of the bump.
In the method of manufacturing a nitride semiconductor light emitting device configured as described above, since the resin sealing body is shaped by polishing and cutting after the resin is cured, the resin sealing body can be processed with high dimensional accuracy. Thus, a nitride semiconductor light emitting device with little variation in dimension of the outer shape can be manufactured.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
As shown in FIGS. 1 and 2, the semiconductor chip according to the first embodiment of the present invention has an n-type semiconductor layer 2 made of, for example, an n-type nitride semiconductor doped with Si on a substrate 1 made of sapphire. A nitride semiconductor light-emitting device in which a light-emitting layer (not shown) made of a nitride semiconductor and a p-type semiconductor layer 3 made of a p-type nitride semiconductor doped with Mg are laminated, and has the following configuration Has been.
[0013]
(Configuration of electrode part)
An n pad electrode 22 is formed on the n type semiconductor layer 2 exposed by removing a part of the p type semiconductor layer 3, and a p full surface electrode 31 is formed on almost the entire surface of the p type semiconductor layer. A p-pad electrode 32 is formed on a part of 31.
Here, on the substrate 1, the protective film 4 made of SiO 2 is formed so as to cover the n-type semiconductor layer 2, the p-type semiconductor layer 3 and the p-full-surface electrode 31 except for the upper surfaces of the n-pad electrode 22 and the p-pad electrode 32. A protective film 5 made of polyimide, for example, is formed thereon.
Bumps 23 and 33 are formed on the n pad electrode 22 and the p pad electrode 32 so that the upper end surfaces thereof are flat and have almost the same height.
[0014]
(Resin encapsulant)
In the semiconductor chip of the first embodiment, the resin sealing body 7 is formed so as to cover the entire element except for the upper end portion of the bump 23, the upper end portion of the bump 33, and the lower surface of the substrate 1.
Here, in the semiconductor chip of the first embodiment, the resin sealing body 7 is formed so as to have the side surface 7a perpendicular to the substrate 1, and thereby the outer shape of the semiconductor chip of the first embodiment is a rectangular parallelepiped. The
In FIG. 2, a portion denoted by reference numeral 7 b is a bottom surface of the resin sealing body 7 formed so as to surround the lower surface of the substrate 1, and is substantially flush with the bottom surface of the substrate 1. It is formed so that it may be located in.
In the semiconductor chip of the first embodiment, as shown in FIG. 1, an electrode layer 24 is formed on the upper surface of the resin sealing body 7 so as to connect the two exposed bumps 23 to each other, and the resin sealing is performed. An electrode layer 34 is formed on the upper surface of the stopper 7 so as to connect the two exposed bumps 33 to each other.
[0015]
In the semiconductor chip according to the first embodiment configured as described above, since the portion constituting the element is protected by the substrate 1 and the resin sealing body 7, for example, destruction of the element during mounting is prevented. It is also possible to prevent the die bond resin from adhering to the electrode surface.
[0016]
Hereinafter, a method for manufacturing the semiconductor chip according to the first embodiment will be described.
In the following FIGS. 3 to 4, the p-type and n-type semiconductor layers and the electrodes such as the n and p electrodes are omitted.
[0017]
(Process for forming each element region)
In this manufacturing method, first, a plurality of elements corresponding to the respective semiconductor chips are formed on a wafer 100 made of sapphire.
Specifically, an n-type semiconductor layer and a p-type semiconductor layer are formed on the wafer 100, and the n-type semiconductor layer and the p-type semiconductor layer located between the elements are removed by etching to separate each element. To do.
Hereinafter, a portion removed by etching between the elements is referred to as an element isolation region, and is denoted by reference numerals 41 and 42 in FIG.
Here, the element isolation regions 41 are formed to be parallel to each other, and the element isolation regions 42 are formed to be parallel to each other.
The element isolation region 41 and the element isolation region 42 are formed so as to be orthogonal to each other.
[0018]
Next, an n-pad electrode 22 is formed on the n-type semiconductor layer 2 exposed by removing a part of the p-type semiconductor layer 3 in each element region to expose the n-type semiconductor layer 2.
Further, a p full surface electrode 31 is formed on almost the entire surface of the p type semiconductor layer 3, and a p pad electrode 32 is formed on a part of the n full surface electrode 31.
Next, a protective film 4 made of SiO 2 is formed so as to cover the n-type semiconductor layer 2, the p-type semiconductor layer 3, and the p-full-surface electrode 31 except for the upper surfaces of the n-pad electrode 22 and the p-pad electrode 32. A protective film 5 made of polyimide is formed.
Then, bumps 23 and 33 are formed on the n pad electrode 22 and the p pad electrode 32, respectively.
[0019]
(Separation groove forming process)
Next, as shown in FIGS. 3B and 5, a separation groove 51 having a predetermined shape is formed on the surface of the wafer exposed in the element isolation regions 41 and 42 using, for example, a dicing saw.
Here, the separation groove 51 is set to a depth of 200 μm and a width of 100, for example.
When the width of the separation width 51 is shallower than 200 μm, the time for dicing can be shortened and the amount of wear of the dicing blade (dicing saw blade) can be reduced. In this case, in the substrate polishing step described later, the polishing amount of the substrate becomes large, so that the polishing time becomes long. However, since the polishing of the wafer can be processed in a large amount (a large number) at a time, there is no particular problem.
However, since the strength of the resin that holds the chip after polishing decreases, it is necessary to set the depth of the separation groove 51 so that a constant holding strength can be maintained.
Conversely, when the width of the separation width 51 is set deeper than 200 μm, the amount of wear of the dicing blade increases and the time for dicing increases, but the strength for holding the chip after polishing improves.
Accordingly, the depth of the separation groove 51 is set to an optimum value in consideration of the strength of the resin and the like.
The resin filled in the separation groove contains a filler, which can soften the resin, suppress thermal shrinkage in the polishing step, and has an effect of making the sapphire substrate difficult to break.
Further, the dicing saw used in the separation groove forming step has a blade thickness larger than that of the dicing saw used in the cutting step described later.
[0020]
(Encapsulation resin layer formation process)
Next, as shown in FIG. 3C, a sealing resin layer 70 is formed so as to cover the entire top surface of the wafer and cured.
Then, as shown in FIG. 4A, the cured sealing resin layer 70 is polished from the upper surface until the upper end surfaces of the bumps 23 and 33 are exposed. As a result, the upper end surfaces of the bump 23 and the bump 33 are flat and have substantially the same height.
[0021]
Next, as shown in FIG. 4B, electrode layers 24 and 34 are formed on the exposed bumps 23 and 33, respectively.
In the first embodiment, as shown in FIG. 6, the electrode layer 24 is formed so as to connect the two exposed bumps 23, and the electrode layer 34 is formed so as to connect the two bumps 33.
As described above, in the semiconductor chip according to the first embodiment, the electrode layers 24 and 34 are formed large to facilitate connection with an external circuit.
Specifically, for example, a resist having openings having shapes corresponding to the electrode layers 24 and 34 shown in FIG. 6 is formed on the resin sealing body 70, and a metal layer is formed on the entire surface by sputtering from thereover. Thereafter, the resist is removed (lifted off) together with the metal layer formed thereon, whereby the electrode layers 24 and 34 having a predetermined shape can be formed.
[0022]
(Substrate polishing process)
Next, the substrate 1 is polished from the lower surface of the substrate 1 until it reaches the bottoms of the separation grooves 51 and 52, and as shown in FIG. 4C, the resin seal filled in the separation grooves 51 and 52 on the lower surface of the substrate. The stop body 70 is exposed.
(Cutting process)
Next, as shown in FIG. 4D, the resin sealing body 70 filled in the separation grooves 51 and 52 is, for example, a central portion of each separation groove using a dicing saw having a blade thickness of 20 μm. And cut along the separation groove.
[0023]
The semiconductor chip according to the first embodiment shown in FIGS. 1 and 2 is manufactured through the steps as described above.
[0024]
In the manufacturing method according to the first embodiment configured as described above, the separation grooves 51 are formed between the elements in the wafer 100, the separation grooves 51 are filled with resin and cured, and the lower surface of the wafer 100 is separated. After polishing until the cured resin is exposed in the groove 51, the cured resin is cut at the portion of the separation groove 51, so that the individual sapphire is cut without cutting the sapphire by cutting only the resin. It can be separated into elements.
In this manufacturing method, a step of forming a separation groove and a step of polishing the lower surface of the substrate are required, but cutting is easier than when a sapphire substrate is cut. Easy to automate.
[0025]
Further, in the manufacturing method of the first embodiment, since it is not necessary to cut the sapphire substrate directly except in the step of forming the separation groove, the semiconductor device can be separated into each element without causing chipping or cracking, and has high reliability. Chips can be manufactured with high yield.
[0026]
Further, according to the manufacturing method of the first embodiment, since the resin sealing body is cut perpendicularly to the wafer 100 in the separation grooves 51 and 52 orthogonal to each other, a rectangular semiconductor chip can be easily manufactured. Can do.
Further, in the semiconductor chip of the second embodiment, since the resin sealing body 7 is processed by polishing and cutting after the resin is cured, for example, the resin layer is formed after being divided into individual elements to form the resin Since the resin sealing body can be processed with high dimensional accuracy as compared with the case of sealing, a semiconductor chip with less dimensional variation of the outer shape can be manufactured.
As described above, the semiconductor chip of the first embodiment manufactured by the above manufacturing method has a square shape and can reduce variations in the dimensions of the outer shape, so that stable mounting can be easily realized.
[0027]
Embodiment 2. FIG.
The semiconductor chip according to the second embodiment of the present invention is a light-emitting element chip using a light-transmitting resin as the resin sealing body 70 and containing a phosphor in the resin.
That is, the semiconductor chip of the second embodiment is configured as follows.
(1) The p whole surface electrode 31 is made of a light-transmitting electrode made of, for example, a thin metal film so that light emitted from the light emitting layer is extracted from the side on which the electrode is formed.
(2) Moreover, the resin sealing body 70 contains a phosphor that generates light having a wavelength different from that of the light absorbed and absorbed by the light emitting layer.
(3) The configuration other than the above (1) and (2) is the same as in the first embodiment.
[0028]
The semiconductor chip manufacturing method of the second embodiment is the same as the manufacturing method of the first embodiment except that a resin containing a phosphor is used as the resin of the resin sealing body 70.
[0029]
In the semiconductor chip of the second embodiment configured as described above, for example, a nitride semiconductor is used as an n-type semiconductor layer and a p-type semiconductor layer, respectively, and blue light is emitted in the light-emitting layer, and as a phosphor, for example, cerium. By using a phosphor such as yttrium / aluminum / garnet phosphor activated in step 1, white light is observed due to color mixture of light emitted from the light emitting layer and light emitted from the phosphor.
[0030]
Since the semiconductor chip of the second embodiment configured as described above is entirely covered with the resin sealing body 70 except for the lower surface of the substrate 1, the chromaticity variation can be reduced.
For example, if the side surface (or part thereof) of the substrate 1 is not covered with a resin containing a phosphor, light emitted from the light emitting layer is directly emitted from that part, and the whole becomes bluish white. However, since the semiconductor chip of the second embodiment can be covered with the resin containing the phosphor without exposing the side surface of the substrate 1, such inconvenience can be prevented.
[0031]
Hereinafter, a mounting example of the semiconductor chip according to the first or second embodiment of the present invention will be described.
Implementation Example 1
Mounting Example 1 is a mounting example when the semiconductor chip according to the present invention is flip-chip bonded (FIG. 7).
That is, in this mounting example, as shown in FIG. 7, the electrode layers 24, 34 of the semiconductor chip are opposed to electrodes (not shown) formed on the mounting substrate 90 and connected by solder 80.
In this example, the emitted light is emitted from the lower surface of the substrate.
When flip-chip bonding is used as described above, the resin sealing body 7 of the semiconductor chip preferably contains, for example, reflective scattering particles such as titanium oxide. When the reflection / scattering particles are contained, light emitted from the side surface of the substrate and the electrode side of the substrate can be reflected by the reflection / scattering particles and emitted from the lower surface of the substrate, so that the light extraction efficiency can be improved. .
[0032]
Further, when used by flip-chip bonding, particles having good thermal conductivity such as AlN may be contained in the resin sealing body 7 of the semiconductor chip. Since heat conductivity can be improved, heat dissipation characteristics can be improved.
Further, when used by flip-chip bonding, it is preferable to use a resin having excellent heat resistance as the material of the resin sealing body 7 of the semiconductor chip, thereby enabling reflow soldering and deterioration caused thereby. Can be prevented.
[0033]
Implementation example 2
As shown in FIG. 8, this mounting example 2 uses a wire 82 made of, for example, Au or Al in order to extract light from the upper surface of the substrate 1, that is, the side on which the electrode of the substrate 1 is formed. It is the example connected by wire bonding.
For example, such a mounting method is used in the semiconductor chip of the second embodiment.
With such a mounting method, the element according to the present invention is covered with the resin sealing body 7 having a substantially vertical side surface, so that the die bond resin 83 wraps around and adheres to the upper surface of the resin sealing body 7 ( Can be prevented).
Here, in this mounting example, an epoxy resin or a silver paste can be used as the die bond resin.
[0034]
In the first and second embodiments, the light emitting element chip using the nitride semiconductor has been described. However, the present invention is not limited to this, and the present invention can also be applied to elements using other semiconductor materials. .
Further, the present invention is not limited to the light emitting element chip, but can be applied to a light receiving element and further to a diode and a transistor other than the light-related element.
[0035]
【The invention's effect】
As described above in detail, in the semiconductor chip according to the present invention, a resin sealing body is formed so as to substantially cover the chip except for the tip portion of the bump and the lower surface of the substrate, and the resin sealing is performed. Since the stationary body has a side surface perpendicular to the substrate, each semiconductor layer and each electrode can be protected, handling at the time of mounting can be facilitated, and the resin-sealed body is attached to the substrate. Since it has a vertical side surface, handling during mounting can be facilitated.
Therefore, according to the present invention, a semiconductor chip that is easy to handle can be provided.
[0036]
Further, a semiconductor chip manufacturing method according to the present invention includes a groove forming step of forming a separation groove between elements of the wafer, a resin formation step of forming a resin so that the separation groove is filled with resin, A polishing step of polishing the wafer until the cured resin of the separation groove is exposed; and a cutting step of cutting the cured resin of the separation groove, thereby polishing and cutting the resin after curing the resin. Since the shape processing of the sealing body is performed, the resin sealing body can be processed with high dimensional accuracy, a semiconductor chip with less dimensional variation in the outer shape can be manufactured, and chipping and cracking can be easily prevented, Moreover, it can be easily automated.
[Brief description of the drawings]
FIG. 1 is a plan view of a semiconductor chip (light emitting element chip) according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG.
3A is a cross-sectional view after forming an element portion, FIG. 3B is a cross-sectional view after forming a separation groove, and FIG. 3B is a cross-sectional view after forming a resin layer in the semiconductor chip manufacturing method of the first embodiment; It is a figure (c).
4A is a cross-sectional view after polishing a resin layer, FIG. 4B is a cross-sectional view after forming an electrode layer for connecting bumps, and a substrate is polished in the method for manufacturing a semiconductor chip of Embodiment 1. FIG. It is sectional drawing (c) after having performed, and sectional drawing (d) after cut | disconnecting the resin layer in a separation groove.
5 is a plan view after forming a separation groove in the method for manufacturing a semiconductor chip according to the first embodiment; FIG.
6 is a plan view after a resin layer is polished and an electrode layer for connecting bumps is formed in the method for manufacturing a semiconductor chip according to the first embodiment; FIG.
FIG. 7 is a cross-sectional view showing a state when the semiconductor chip according to the present invention is flip-chip mounted.
FIG. 8 is a cross-sectional view showing a state when a semiconductor chip according to the present invention is mounted using wire bonding.
[Explanation of symbols]
1 ... substrate,
2 ... n-type semiconductor layer,
3 ... p-type semiconductor layer,
4, 5 ... Protective film,
7 ... Resin sealing body,
7a: side surface of the resin sealing body,
7b: bottom surface of the resin sealing body 7,
22 ... n pad electrodes 23, 33 ... bumps,
24, 34 ... electrode layers,
31 ... p full surface electrode,
32 ... p pad electrode,
41, 42 ... element isolation region,
51, 52 ... separation groove,
80 ... Solder,
82 ... Wire,
90 ... Mounting board,
100: Wafer.

Claims (5)

An n-type semiconductor layer in which an n-electrode is formed on a substrate, a light-emitting layer made of a nitride semiconductor, and a p-type semiconductor layer in which a p-electrode is formed,
In the nitride semiconductor light emitting device in which bumps are respectively formed on the n electrode and the p electrode,
A resin sealing body made of a resin including a phosphor and having a light-transmitting property is formed so as to substantially cover the chip except for the tip portion of the bump and the lower surface of the substrate, and the resin sealing body is the above-mentioned A nitride semiconductor light emitting device having a side surface perpendicular to a substrate.   2. The nitride semiconductor light emitting device according to claim 1, wherein the n-type semiconductor layer includes one or more nitride semiconductor layers, and the p-type semiconductor layer includes one or more nitride semiconductor layers.   3. The nitride semiconductor light emitting element according to claim 1, wherein the resin sealing body has a bottom surface that is positioned substantially on the same plane as the lower surface outside the lower surface of the substrate.   The nitride resin light-emitting element according to claim 1, wherein the resin sealing body includes reflective scattering particles. A method for manufacturing a nitride semiconductor light emitting device by separating a plurality of devices formed on a wafer for each device,
A groove forming step of forming a separation groove between the elements of the wafer;
A resin forming step of forming a translucent resin on the wafer on which the separation groove is formed and filling the separation groove with resin, and curing the resin;
A polishing step of polishing the lower surface of the wafer until the cured resin of the separation groove is exposed;
A cutting step of cutting the cured resin of the separation groove,
The nitride semiconductor light emitting device includes an n-type semiconductor layer in which an n-electrode is formed, a light-emitting layer made of a nitride semiconductor, and a p-type semiconductor layer in which a p-electrode is formed on a substrate obtained by cutting the wafer. And comprising
Bumps are respectively formed on the n electrode and the p electrode,
In the resin forming step, a phosphor is contained in the resin, and the resin is formed so as to substantially cover each element except for the tip portion of the bump. Method.

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